Hydrodynamic machine



Sept. 2,

I NVENTOR. WALTER FERRIS Sept. 2, 1952 W FERRIS `2,608,934

Filed oct.- 27, 1945v 5 sheetshee; s,

FIG. 3

Fle. 4

FIG. 5

' INVENTOR.

WALTER FERRIS Patented Sept. 2, 1952 sTAfT-Es PATENT OFFICE Tinz-DRoDYNAlmo MACHINE wa'lter Ferris Milwaukee," Wis., assignor to The Oilgear Coinpany,ltiilwaukee,Y Wis., alcorporation of'Wisconsin f ApplcatibnOctober 27 11.C1airi1s.

.Thiseapplication is.-afcontinuation-inf-parti of pplicationV Serialwlifo.4 618,288,"fnledeseptember The invention relates atozihydrodynamic :.maachin'es of thefs-typefhavingjcylindersfarranged in. fea; rotatable: ylinder barreLfpistonsa-tted inthe 1: :':cylinders with LV:their fouter l:ends i in. engagement wi-thea:L thrustfvmemberk which ,is `eccentric to l:the tfcylinderfbarrelaand :causes 'thepistons toreciprocate'in. their cylinders'fduringxrotationf-offthe ffcylindembarreLand afzfvalvefifor `controlling the #ffoW-of liquidi: tofzanid .-fromthe cylinders.

,-:More. particularly, :fthe i:invention relates Y Vto la f' xhydr'odynam-ic machine offthe rollingvpistontype. Yhaten-is;a'fmachine havingfancannular i'reaction '-Isuriace farranged:upon its zthrustfmember and en- --gagingathe'outer endzoffeachfrpiston'npon a-.si-ngle spot which is offset farfenoughffromz-thefpiston :faxis'to causeqthepistonf'to rotate-imite cylinder itreciprocates-.thereimvsuchvas the hydrodysnamicfmachine described'fandclaimed:in Patent 'f-In the f-.m'achineshown-4 in `the l 1 above rwpatent, -Vfthe cylinder :barrel: rotates upon apsha'ft or pintle which .-constituteslrthe valveA Yfor :controlling :the alowfofliquid to and :from the `cylinders but-ama- :fc'hines-fof y the-f rollingY piston ftypefareea-lso made ,-:Witli'at valves'ononezor,both-ends of the cylinder barrel to control theiilowf'oi-.-'liquidJto and if. from the";cyl-inders`,-wsuchiA as the -machine vshown n- Patent No-.-;2;2'73-,468 ;"and thelpresent :invention -:particularly'applicableto farolling-piston maifrchineiof;theat--valvestype .-fAvrnachinefof therolling pistontype will function as'-azpun'ip'y When'fitisdriven-mechanically @and :itf willfunctien'fasa :hydraulicmotor when itis zsupplied vvithf'liquidfunder pressure.v ASince the tunction-fofapumpand'the functionof aimof1t0rs aresubstantiallyoppositeJtofeach other,l a 4machine;\embodyingnthe invention Awill-beex-` :ij 'pla-inedfanda:referred,to he1-ein--.as%` agpump lbut it :is tov befunders'toodfthatY .theV invention is 1:equally v"applicable to arinotor :'a'ndris innoiiwayzlimited EL'ifto'apump. i When-ifa roll-ing:pistonzipurnp: is: Iifseachiipisto'ir'.moves Aovftward:fand its? cylin'cl'erfis snppliedwvitli li'qtiidfduring onefhalfiof eachrevo- 'I flutinfoff thecyli'ndr barrel; sand the" thrustlmeiniber-ifrcs L'the'`ffli`istn"inward and causes-` it to flel-"lliq'uidJ from "itsfcylinder 'during the `other' half of each revolution-ofthe cylinder barrel.

*Duet-to theieactionrsurface engaging each ston upna'- s'inglef spot, the 'fpumping force transni d throughthe piston is limited 'by the l'iri'igrhefthatfspot. 4 If thepump-is ide# "in-:operation wis-serial No.- 625,027

2 l:signed to createpressures below amoderatyalue such as 1200 pounds persquare inch,.eachfpi ston -may be headlessand ofsuch diameter that .the contact spot may be located far enough from the vpistonj axis to cause the pistonA to rotate-aait reciprocates. If the pump is .designed tdcrea-te f pressuresup to a high valuesuch as 3500 p. sli., theV pistons mustvr be lreduced in diameter accordingly in order to keep the maximum pump- "i-ng force Within the'bearingvalue of the contact spot and each piston mustxbe provided withan enlarged head; as shown injPa'tentNo. 2,074,068, in order that the contact spot may. be located,far enough from the piston axis to cause-fthefpiston ,to'rotate as Yit reciprocates.

Rolling piston pumps with large heads operate successfully in pumps designed tocarry pressures up to the maximum 'ordinarily required bntfin a pump designedtocreate veryfhigh pressures, 20 such as `6000 p. sui;` each piston` would VVnecessarily be so small in diameter that ltheldistane betweenv itsaxis andthejcontact spot Would'lbe sogreat relativeto v the Yradiusjof the pistons that there Would be grave-danger.offthefhead breaking off when the pump Wasfrequiredtocreate avery high pressure. The present invention has as anlobject'to pro- `vide a rolling piston pump which cancreate zhigh `pressures 4.Without Vdanger of .breakinglifts rpistons. p s p Another object is toemploy leakage liquidior 5 .holding the pistons against the thrust member.

,Af pump Yconstructed according .to thev invention-has the advantagethat its pistonsare'so well guided that the danger of the. transverse components of the Vpumping forces causing the outer `ends of -the cylinder. bores towear ut'of round Vis substantially eliminated. n

- '.These andA other obj ectsv and A advantagesi x'vill Y be apparent from thedescription.hereinafter wgiven'ofapump infWhich the inVentionismbodied. A

,Accord-ing to the invention iniitsfgeneralaspeet, a rotatable cylinder barrel is provided-with a rplurality of Vcylinders each .'of` which ,includes acpumping portion and anon-pumping?portion pf: rdifferent tdiameters with the --smaller portion *inward from :andrcomm'unicating' withV theflarger portion; a-piston is -ttedv-ineach Vcylinder and 50 I'includes'two Vportions of different idiameters t- @ted-respectively in the two portions of'the'cylinder, a' thrust member engages' the Jouter ends-tof "the fpi'stons" and causes each apisto'n tomove'fin- Ward'and outward lalternately 'asthe'iylinder 55 @barrel rotates, thepunlpingsportionsofffthecylinders are connected through a valve to an external circuit, the non-pumping portions of the cylinders are connected to each other, lthe in- Ward moving pistons eject liquid from the pumping portions of their cylinders to an external circuit and from the non-pumping portions of their cylinders to the non-pumping portions of the cylinders which contain outward moving pistons. The smaller inner portions of the cylinders may be the pumping portions and the larger outer portions may be connected to each other as shown in the drawings, or the larger outer portions of the cylinders may be the pumping portions and the smaller inner portions be connected to each other as shown and specifically claimed in application Serial No. 618,288.

The invention is exemplified by the pump shown somewhat diagrammatically in the accompanying drawings in which the views are as follows:

Fig. 1 is a transverse vertical section through a pump in which the invention is embodied, the plane of the view being indicated by the line I I of Fig. 2.

Fig. 2 is a central longitudinal section through the pump taken on the line 2--2 of Fig. 1, the view being inclined to the vertical center line in order to show the hold-up motors for the valve.

Fig. 3 is a Vertical elevation of the Valve which f controls the flow of liquid to and from the cylinders, the plane of the view being indicated by the line 3 3 of Fig. 2.

Fig. 4 is a vertical section through the valve taken in the plane indicated by the line 4 4 of Fig. 2.

Fig. 5 is a Vertical section taken in the plane indicated by the line 5 5 of Fig. 2.

For the purpose of illustration, the invention has been shown embodied in a radial pump of the flat valve type but it may be embodied in other types of hydrodynamic machines.

Y The pump chosen for illustration has its mechanism arranged within and carriedgby a casing I of suitable construction. Casing I encloses a rotatable cylinder barrel 2 which is fixed to a shaft 3 in any suitable manner such as by shaft 3 having a flange 4 fixed to or formed integral therewith and rigidly secured to cylinder barrel 2 as by being bolted thereto. Shaft 3 extends outward through casing I for connection to a source of power and is journaled in a thrust bearing 5 carried by casing I. Cylinder barrel 2 is provided with a plurality of radial cylinders each of which consists of a small diameter inner bore 6 and an outer concentric bore 'I of larger diameter. The cylinders have been shown arranged in two circular rows with the largest odd number of cylinders in each row that is practical but the pump may have only a single row or a larger number of rows of cylinders depending upon the volumetric capacity desired. f

The cylinders in one row are offset one half of the cylinder spacing from the'cylinders in the other row and the inner end of each bore 6 in the front row communicates with a passage 8 which also communicates with the inner end of the adjacent bore 6 in the rear row and extends rearward through cylinder Ibarrel 2 and flange 4. Likewise, each bore 'I in one row communicates at its inner end with a passage 9 which is formed axially in cylinder barrel 2 and also communic'ates with the inner end of the adjacent bore 1. in the other row. Each passage 9 communivcates with a passage I0 which extends radially inward into communication with an annular groove II which is formed in shaft 3.

Each cylinder 6 1 has a piston fitted therein. Each piston includes a small diameter portion or pumping piston I2, which is closely fitted in the bore 6 of that cylinder, and a larger concentric guiding portion I3 which is closely fitted in the bore 'I of that cylinder and forms an annular shoulder I4 at its junction with the small portion I2. During rotation of cylinder barrel 2, pistons I2 I3 will reciprocate in cylinders 6 1, liquid will flow through passages 8 to and from bores 6 and liquid will flow through passages 9 and I0 to and from bores 'I as will presently be explained.

Cylinder barrel 2 is adapted to be rotated from an external source of power by shaft 3 and it is supported for rotation by bearing 5 and by a ball bearing I5 the outer race of which is fixed in casing I. In order to keep the overall length of the pump at a minimum, flange 4 is arranged within a suitable recess formed in the rear end of cylinder barrel 2 and bearing I5 is arranged radially outward from ange 4.

During rotation of cylinder barrel 2, pistons I2 I3 are reciprocated in their cylinders by an annular thrust member I6 which is eccentric to cylinder barrel 2. For the purpose of illustration, thrust member IE has been shown as being rotatably supported within a ball bearing Il which has its outer race xed in a stationary position Within casing I but the thrust member may be rotatably supported within a displacement varying member or slide block which is shiftable transversely of the cylinder barrel axis to vary the displacement of the pump according to common practice and as shown in the patents referred to above.

Thrust member I6 has two beveled reaction surfaces I8 formed upon the inside thereof at acute angles to the respective piston axes and each surface engages the outer ends of the pistons in one of the circular rows. 'I'he outer end of each piston I2 I3 is so shaped and of such a size that it engages a reaction surface upon a single spot which is offset far enough from the piston axis to cause the piston to rotate in its cylinder as it reciprocates therein as explained in Patent No. 2,074,068.

For the purpose of illustration, pistons I2 I3 have been shown as having enlarged heads upon their outer ends in order that the contact spot may be located far enough from the piston axis to cause the pistons to rotate, reaction surfaces I8 have been shown inclined in opposite directions relative to the cylinder barrel axis, and pistons I 2 I3 have been shown arranged upon radii of the cylinder barrel. However, the outer portions I3 of the pistons may be made large enough in diameter to avoid the necessity of providing enlarged heads, reaction surfaces I8 may be inclined in the same direction, or the reaction surfaces may be parallel to the cylinder barrel axis and the pistons inclined to the radii of the cylinder barrel as shown in Patent No. 2,273,468, the term radial as used herein being intended to apply to a piston whichy extends through the outer periphery of a cylinder barrel inward toward the axis thereof regardless of whether the piston is upon or inclined to a radius of the cylinder barrel.

Due to thrust member I 6 being eccentric to cylinder barrel 2, each piston I2 I3 will move progressively outward during one half of each revolution of cylinder barrel 2 and it will be forced @progressively nwardiudurin Ithexrother .halfe'of "'chlrevolutiontoficylinder arrehz'. Liquidwill Tifflowiintoithebloresf' and liirrwhcl'ilithezoutward .rnovi'ngipistonsflereznttedfandithezinwardinrmzing 'it-wolldiametricllyfaopposedi arcuate; portszfzaleandfwith which message@3iregistersuccessivelyas r-ryliiiol'eiffloerreli 2=-rotetes- The outer facelffflange 4 constitutes e seat for valve 20 but, if-sheti 3 lf--weretetttchedto @cylindewbafrrelz' ink a'different "and'smooth yandthe dbutfting'surfaceson member '5h30-and Apiston-(29 are"ordinarilyiground"spherical 1 -end smooth soithat=membeii@magy-provide:esubfstantiellyiliquid'f tightjoint between1pistorif-2`9fand valve 20 irrespective of slight errors'lintolinement and the cylinders 28 of bot p @communicate-wither passag- 3 iwhich arefrformed `irrrca'singf t-end? adapted ltoi-b 'c'onner-zted"42011011- ifposi-telsidesfof the '-hydreiilicfcircitasf-indicated by the two pipes 34 and 35.

nene' ear 4endvofayalvell into communicationwthlp'ort 2&2 Ilgsfand the'ellenedlopeningsgthrough.theilpistonZB -@andamembertofeeachshfildeup motor f21=register with;aiipassagefs'tiwhichfextends throughltherear l.

1v Tiereny arrangement 'iis isu'ch'ithat kliquid'imay -flowsireely betweenzzport I" 'andmipe Mfandv'bef .tweenV port; 2 2' xand ipipez'. muy .fpressureiprevailingrin porti-.2 leazicts :uponthepistonsi29'zof both f fholdeupfmotorsf uandlzanyrpressure preuailingin porteZfZe acts.tupon'-thepistons-'LZ 9` iofiboth; fh-oldeup v motors 2 Tlf andv eeuses'yalve 20 .to zbeinrgedz-agazinst -.-itsf-seat a force rwhichzfisvproportionanmio:pump

--fbya. holdeupy iorceaconsisting of-vitwor fctorsone otwhich `is suppliedibyi springsr la andgisconstant l Vand thefother off-whiclrfisf .supplied -'bytheiimotive liquidfendfvaries.ineccordencefwitlc yariationsin -vpump pressure. I l

l In the pump; shown,the1 holdeniprforce'atendsato l move cylinder ber-teli, 2:. l:.etxietllyf. toward the '-iright Y butA is -preventedfrom fdoingrsoitbyfthrustibeering A5, -Whi-lerfthis arrengementiri 'tisfactoryein d-upfmotors? 21X but iit Imayfbel l h'its topeningisubstanitittllysin fhold-upiforces are thusgopposed anditheicylinder .barrel.isfhydrostatioallybalanced;axially;

When4 cylinder barrel 2 .is -rotatedin :a clockwise 4direction in respect .to Eig.l, thrustfsmember'vl willlforce the pistons f I 2-'1 3` in contactfwith-'the upper halfc thereof f progressively inward and-fthe pistons |2-I3 in contactwith/the lcwtershalfarof lthrust member :Iii-will fmove-progressively'f'zout Werddue to thrust member -Ifibeing eccentricvto cylinder barrel 2.

The bores 6 of r the cylinders"v containingfthe outward-:moving Apistons-willibe-filled=.with'1lir:1uid

-which flows thereto through passages :8, 'valve port l2:2, passages f 31; hold-up motors 21 :andinassage `33- frompipef. Theinwardm'ov'ing pistons .I2-43 will eject vliquid fromethehores 6 ioftheir cylinders throughpassagess18,ivalveportZ Iprpaspipe .3G-.and will -eject'liquid frombjores 1 :of their cylinders through?passages1 49 vend-1 llfandifgrooye -ll toV thebores l of the cylindersfcontainingl'the outwardmoving pistons.

The volume of lliquid-ejected from' fthe'- loores" l bythe inward `moving` pistons isV exactlyfequallrto thev volume required to fill lthe? bores l lof' the ,cylinders containing Ythe outward'l LInovingapistons. However, l"when the. pump-fis;.creatingr a i high: pressure; there will? ibe e" slightleaka'gefof Yliouid from thefbores BV to Athe bores" 'l off'ech cylinder containinganiinward moving ipistonlfsfso that the'xliquid' owing intol igroove'fl riss-infericess `of the Volume: required 'to ll. thel bores of y the. cylinders. containing` the `ol1twardrmoving #pistons .'Inlcrder toi provide! fortheescapei'of v thisexcess liquid,` er duct-.38" extendsrraldiallyiinv:piston vIzZ- ri351110011 Yai singlelspotwhichifis oli?- `set-far enough from vtherpiston:exis:.toicetuse Arecettes therein, .1a-ndi the zforce i which cani-tbe tramsrnittd from z the thrust member. toli '.liq-

`uid r-in the `cylinder is wlimited' sbylth bearing Value of that spot. THe-Wever;fthelforcefwhich 'must'fbe transmitted through: a goisten'rto create l a given pressure :isproportionaloto fthe' eiective pumping-eres of ,the 'pistonrimultiplied the pressure and;V since "the Tarea; -of piston p v on V-I2 `isisrnetllyevery fhighrpressure canbefcife- `:ated 'without exerting. .uponzzeech piston ai *leed in excess of the bearing *value y'of fthe @contact spot.

Sinceaeach piston engages an inclined reacf vtion;surtecei 8 upon v a spot-which isibffset-'from thefpistonfexis 'the pumpingL force isefppliedrto the piston ate right angle-to`- the'inclinedfreac- "rithe resistance er1-the! liquid against' -tlie-` 'end "of portion I2 which causes the pumping force to Ibe resolved into a radial component which forces the piston inward and a lateral component which causes the piston to bear against one side of the cylinder. However, guiding portions I3 are relatively large so that the |bearing surface of each piston is much greater than on the conventional rolling piston, and the tendency of the cylinder to wear out of round is thus negligible. When outward movements of the pistons of a Y radial pump are dependent solely upon centrifugal-force, a piston sometimes will not move progressively outward as the cylinder barrel rotates but itV will hesitate until its outer end is a substantial distance from the reaction surface and then it 'will move outward suddenly and strike the reaction surface with considerable force, thereby creating objectionable noise and tendingto deform the end of the piston and/or the reaction surface. Such a condition frequently results when the motive liquid is overheated and hence generates gas bubbles, or when air is enage liquid from passage 38. The pistons may be initially urged against the thrust member by supercharging the pump if it is small or if it is connected into a closed circuit but, if the pump vis large and is -connected into an open circuit,

supercharging is not practical.

For the purpose of illustration, the pump has been shown as having a foot valve arranged in a bore 39 which extends through valve 20 into communication with passage 3B and has a suitable valve seat at its inner end. The foot valve includes a resistance valve 40 which is urged against the valve seat by a spring 4I and has an axial passage extendingr therethrough, and a check valve 42 'which controls the passage through valve 4) and opens in a direction opposite to that in which valve 40 opens.

The arrangement is such that check valve 42 will permit liquid to flow substantially freely from bore 39 to passage 38 but will prevent liql uid from flowing from passage 38 into bore 39 Without raising valve 46 against the resistance of spring 4I which has sucient strength to hold valve 49 to its seat until the pressure in passage 38 reaches a predetermined maximum, such as 100 p. s. i. The pressure in passage 38 also acts upon the front end of valve 20 and increases the blow-off force tending to move valve .2G away from its seat but this increase in blow-on" force v may .be compensated for by correspondingly increasing the tension of springs 3 I.

In order that pistons I2-I3 may be initially moved into contact with thrust member I6 independently of centrifugal force, the rear end of bore 39 may communicate with a tube 43 which is fixed to valve 20 and extends through the rear wall of casing I with suiiicient clearance to permit-valve 20 to bear uniformly upon its seat. Tube 43 may be connected by a channel 44 to the outlet of an auxiliary pump 45 which draws liquid from a reservoir 46 and discharges the liquid delivered by it in excess of requirements through a low pressure relief valve 41.

Auxiliary pump 45 has been shown as being separate from the main lpump but it may bearranged within casing I and driven in unison with cylinder barrel 2 according to common practice. Also, auxiliary pump 45 may be employed to supercharge the main pump and to supply liquid for control purposes according to common practice.

When the pump is started, liquid from auxiliary pump 45 will flow through channel 44, tube 43 and bore 39 past check valve 42 and through channel 38, groove II and passages I0 and 9 into bores 'I and exertsufiicient force upon shoulders IIIv to force pistons I2-I3 against thrust member I6.

As previously explained, rotation of cylinder barrel 2 causes the pistons I 2-I3 on the discharge side of the pump to be forced progressively inward and to eject liquid from the bores 6 and 1 in which they are fitted. The liquid ejected from bores 6 flows to the external circuit while the liquid ejected from bores 1 ows to the bores 1 on the intake side of the pump and causes the pistons therein to move outward.

When the liquid discharged into the external circuit meets resistance, pressure rises and causes a slight leakage of liquid from the bores 6 into the bores 'I on the discharge side of the pump. Since the volume of liquid expelled from the bores 'I by the inward moving pistons is equal to the volume required to ll the bores I in which the pistons are moving outward, bores 'I are at all times iilled With liquid so that the liquid leaking from the bores 6 into the bores 'I must escape therefrom through duct 38, resistance valve 40, bore 39, tube 43, channel 44 and relief valve 4l into reservoir 46. The resistance of valves 40 and 4'I causes the creation of a pressure which acts upon shoulders I4 and holds pistons I2-I3 against thrust member I6 with a force proportional to the pressure required to open valves 49 and 41.

The pump disclosed herein is thus capable of developing Very high pressures and its pistons are at all times positively held in engagement with the thrust member.

The invention herein set forth is susceptible of various modifications and adaptations without departing from the scope thereof which is hereby claimed as follows:

l. In a hydrodynamic machine, the combination of a rotatable cylinder barrel having a plurality of two-diameter cylinders, each of said cylinders including a pumping portion and a concentric guiding portion one of which is larger than the other and is arranged outward therefrom, channels communicating with said pumping portions, valve means associated with said channels for controlling the flow of liquid to and from said pumping portions, a two-diameter piston arranged in each of said cylinders and having its larger portion fitted in the larger portion thereof and its smaller portion iitted in the smaller portion thereof, a thrust member engaging the outer ends of said pistons and so arranged in respect to said cylinder barrel as to cause the pistons on one side of said machine to move progressively inward during rotation of said cylinder barrel and to eject liquid from both the pumping portions and the guiding portions of the cylinders on that side of said machine, channel means for interconnecting the guiding portions of all of said cylinders to enable liquid ejected by inward moving pistons from the guiding portions of the cylinders on said one side of said machine to now to the guiding portions of the cylinders on the other side of said machine and move outward the pistonsnin.:thosencylinderszand; meansfa'foriipersescape; Aof 'liquidar and therclay.:Ina'intainz linz: said.

guidingfportions aluidz'pressure which holdsithe pistonsfiion` Lsaid other:sidesoftsaidt 'machine win contactlwith saidzthrust member.

' .22 In ..=a ihydrodynam'ic"machine;lthezcornbina= tionifof a 1rotatable'cylinder barrels having@ plurality of1Jtwoaiiametervcylinders, :eachbfot said. cylinders Fincludingiaapumpingiportionzandfal cone oentriczguidng np'ortion.'l oneflof Whiolraisf larger than therrother and is Larranged'foutward: theretrom';-1:channe1s communicatina:futithsaidA pumpngllfportions, :valve f means-1 iassooiated.: with ilsa'idf channels i forscontrollingsltheow 4of iliquidztoiand; fromfsaidlpumping rportions, aaftwoediameterfpise' tonfarranged:ineachrofnsaid: cylinders=and having its slarger:z :portion ttedifin Lthel:larger-importiert thereof .ia-nd .zits smaller. portion:1fittedf'.fi1r..the smaller portion thereof, a thrust memberfzene gaging theiouterxendsmisaidrpistonsiandlso arranged inA arespect Lito .-sadf1 cylinder :fbarrel .saszizto causel the I pistons on'.;one`=.sidei `oi said 'lmaohine to v: :move :progressivelyinwardrduring.irotationx-of saidroylinderrbarrel and 'to-eject liquid .ffrom't'both the:.pumping;portions zandritherguiding .portions of -the cylindersl orrrzzthat'sideiaof:'saidiimachine,

channel lmeansftfor rinterconneotinggthe@guiding portions of f.a1l;=off=:s aid cyliriders :to enableili'qui'd ejected Lb t .inward moving ',pi'stons ifrom .thes guid inglportionsl-ofrurthe cylinders-oon saidoonezfisidefof said machineato .-flowztozthetguidngfportionsfof the cylin'dersronthe nth'errside of .saidfmachine Y andgmovetoutwardztle pistonsin thoseicylinders, alsourceofpressurelliquidothenthanrsaidylina ders;.and 'meansforzsupplyingliquid fromnsaid sourceito theifguidingiportionsnf said cylinders sto initially moveJsaid pistons .outwardiintoccontact l .JL-3.1. Infra:hydrodynamicemachinef theicombinaition'iofa rotatable'foylinder barreli-havin'g :alpin-'e ralityxof :twoadiarnetertoylinders; eachof saidl'cyl- .inders :including :awpumpingfzportiort andialz'cone ingfaportions; valveifrneans associate channels"A1 forffcontrllingl-lthesilowroffliquidfto and romzisaidtpumping Atportions, a: twodiaxneter ylois-` .tonv arrangedfineaChtof-isai' cylinders :and havlingits 4langer portionattedinlthe larger" portion thereofandl lits smaller pontiowfttedfi .'-ithe smaller lportionlzhereo`f-,fa thrust member -:engaging:thenuterfendsbonsadpistonsandfsoarranged infrespect fto said-fcylinderkbarreltas to-l causerth'e .pistons fornoneesidemff'saidfmachine to nioveLp'roe grossit/elylinwamtw during frotationlof-s'ai'clz cylinder floarrel- 'an'dto eject liquid' ifromflboth Lthef-flournnL ing portions anir-theoguiding portions-'ofl the-oyl Ainders orrlthaty rsid foi Sksaidftmachine; :channel Ameans flfor interconnecting thefeniding portions :of-all "of'isaid `:cylinders tof1enabl lliquidil'ejected -byi-inward:movingepistonsinform-the g'uidingqsor'- tions :of: the cylindersgonf :saidloneesde ofsaid :machine'ffto flowfto-.tthen eguidingfiportions tot fthe .'cylinderszonfthefother. side'fof'isaidrmachneoand .fnrove outward:.itheiapistonssiinathosencylinders, -meansf for tperrnittingwescape from .sai'd guiding zportions; of:.aliqnidclleakingzzsthereintofffromrsaid pumping portions; includingrarresistancefvalvezto resist isaidses'capeaof liquid anittherehyimaintain .ingfsaid uidinaportions rairllluid'gpressure :which holds sthe -pistonstonf'saidlotherfsiderof# e saidl mapnrtionfrthereot, .a thrust fmemherir eneasinalthe outereends .ofnsao-fpistons and:` so :,arrangedlin nie-z smentito said-cylinderharrehas toecause thepisf-` tons on one-.sideof` said: machine to move-pro gressively inward durngrotation: of.;saidtQy1nder barrelfandtto eieotfliquid from lboth-r the-:pumping portions-and the;j guiding `portiorlsof :the-Qylndeis on that side -ofsaid (machinachannelffmeansfor interconnecting thegguidingffportionsfof'alllof said cylinders f-to `:enableA -lignidfejeoted thy; inward movingspistons from .the '1 guiding, l.portions @of the ,oylindersfon saidlone side-of saidtmachine t f1 tor-the guiding portions ofy ithe.fcyalinders otherside otsadrmach-ine-fandfmoyetoutwar .the pistons in those rnzlinders,V and r-meansuor nerrnitting-l `escape Vfrom vsai-ri Ygiyiiding.. portions of liquidk leaking therentonfrom said purnping nortionsinoluding a resistance zvalvetto resistvsaid escapeaof -livquid; ,an-di: thereby --maintain in said guidingportions: a initio-,pressure which: ho1d theupistons .on Asaid other ,side ofr `said-notturni .in contact y,with saidlthrustfmemoer.

5. In` a .hydrodynamicAmachne,,the no oniloinaf tion oftafrotatabietcynnder barreifhanngtsiplu rality..of4 ,two-diameter ;jcylnders eachfto which ,includes fan outer Vguidi-rigportion and ascoli@ centric inner pumping 1portionsoffsrnaller dia-mesV ter, channels communicating withesaid .pumping portions, .valve-means .associatedr-with. saidcham nels `for.,.controllingsthe @flows of 'liquidita-land from saidtpumping-portions, aftwoedamete pis lion arrangedin-each of= saidtoylinders and haring its V larger portion ntted. `lin i the lguiding no'rtion thereof` and itshsrnaller portion.y -tted in` the pumpinglportion. thereof, .a thrust rmember en.- gaging A,the outer v ends or said pistons1andfsmarl-V ranged in respect y.to saidncylinder barreltas ,to Mcause =lthe .pistons on. one vsid-e'. of said-machines!) moverprogressivelyinward during rotation-pisani cylinder A `barrelanti Ytcl-reject -.liquidrom-both ,theDumping;portionsandfthe guidinglnportionrs'xof the cylinders onth'at siderof .saidfmaehneihananel; means @for f. interconneating `the :guiding tions of all of said 'cylinders to enableliquid ejectedbyL-inwardimoving pistonsfirom .theguidingfportions of.A the cylinders onfsaid'tone side of said-machine .-tto Kflow v to Athe gndingeportions f of A'the cylinders on. .thee other side :of V:said machine .and move y outwardv`lthe pistons in those cylinders; vmealflsior :permittingtescape `yfromesad guiding portions. of@ liquidy leaking theneinto "vl-froml f:Said pumping: portions ,includingra resistance namento rosistnsaidfescape iovfrliquid andftherebwmaintan .in saidoguiding iper-tions a@fluidwnressurevwhch holds :thefpistons on= said-:other sideszofosadtma'f chinencontacttwith tsaidtthrfust xnembenras sourire of"pressurediguidwotherfthanfsaid cylindersnand l1 means for supplying liquid from said source to the guiding portions of said cylinders to initially move said pistons outward into contact fwith said thrust member.

6. In a hydrodynamic machine, the combination of a rotatable cylinder barrel having a plurality of two-diameter cylinders arranged therein in a circular row, each cylinder including an outer bore and a smaller inner bore, a two-diameter piston arranged in each cylinder and having its larger portion tted in said outer bore and its smaller portion iitted in said inner bore and forming a shoulder at its junction with said large portion, an annular thrust member arranged eccentric to said cylinder barrel and engaging the outer end of each piston to cause said piston to reciprocate in its cylinder during rotation of said cylinder barrel, a channel communicating with each of said inner bores, valve means for controlling said channels to thereby control the oW of fluid to and from said cylinders, channel means for connecting said outer bores to each other to enable uid expelled from the outei` bores on one side of the machine by inward moving pistons to ow to the outer bores on the other side of the machine and move outward the pistons therein, and means for permitting the escape from said channel means of iiuid leaking from said inner bores into said outer bores including a resistance valve to resist said escape of iluid and thereby create a fluid pressure which acts upon said shoulders and holds said pistons in contact with said thrust member.

'7. In a hydrodynamic machine, the combination of a rotatable cylinder barrel having a plurality of two-diameter cylinders arranged therein in a circular row, each cylinder including an outer bore and a smaller inner bore, a two-diameter piston arranged in each cylinder and having its larger portion tted in said outer bore and its smaller portion tted in said inner bore and forming a shoulder at its junction with said large portion, an annular thrust member arranged eccentric to said cylinder barrel and engaging the outer end of each piston to cause said piston to reciprocate in its cylinder during rotation of said cylinder barrel, a channel communicating with each of said inner bores, valve means for controlling said channels to thereby control the flow of iiuid to and from said cylinders, channel means for connecting said outer bores to each other to enable fluid expelled from the outer bores on one side of the machine by inward moving pistons to flow to the outer bores on the other side of the machine and move out- I i ward the pistons therein, a source of pressure fluid other than said cylinders, and means including said channel means for supplying to said outer bores from said source iluid which acts upon said shoulders to initially move said pistons outward into contact with said thrust member.

8. In a hydrodynamic machine, the combination of a rotatable cylinder barrel having a plurality of two-diameter cylinders arranged therein in a circular row, each cylinder including an outer bore and a smaller inner bore, a two-diameter piston arranged in each cylinder and having its larger portion tted in said outer bore and its smaller portion tted in said inner bore and forming a shoulder at its junction with said large portion, an annular thrust member arranged eccentric to said cylinder barrel and engaging the outer end of each piston to cause said piston to reciprocate in its cylinder during rotation of said cylinder barrel, a channel communicating with each of said inner bores, valve means for controlling said channels to thereby control the flow of iiuid to and from said cylinders, channel means for connecting said outer bores to Veach other to enable fluid expelled from the outer bores on one side of the machine by inward moving pistons to flow to the outer bores on the other. side of the machine and move outward the pistons therein, a source of pressure Iiuid other than said cylinders, means including said channel means for supplying to said outer bores fluid which acts upon said shoulders to initially move said pistons outward into contact with said thrust member, and means for permitting the escape from said channel means of fluid leaking from said inner bores into said outer bores including a resistance valve to resist said escape of fluid and thereby create in said outer bores a iiuid pressure which acts upon said shoulders and holds said pistons in contact with said thrust member.

9. In a hydrodynamic machine, the combination of a rotatable cylinder barrel having a plurality of two-diameter cylinders, each oi said cylinders including a pumping portion and a concentric guiding portion one of which is larger than the other and is arranged outward therefrom, channels communicating with said pumping portions, valve means associated with said channels for controlling the flow of liquid to and from said pumping portions, a two-diameter piston arranged in each of said cylinders and having its larger portion fitted in the larger portion thereof and its smaller portion tted in the smaller portion thereof, a thrust member engaging the outer ends of said pistons and so arranged in respect to said cylinder barrel as to cause the pistons on one side of said machine to move progressively inward during rotation of said cylinder barrel and to eject liquid from both the pumping portions and the guiding portions of the cylinders on that side of said machine. channel means for interconnecting the guiding portions of all of said cylinders to enable liquid ejected by inward moving pistons from the guiding portions of the cylinders on said one side of said machine to flow to the guiding portions of the cylinders on the other side of said machine and move outward the pistons in those cylinders, a source of pressure liquidother than said cylinders, and means for supplying liquid from said source to the guiding portions of said cylinders to initially move said pistons outward into contact with said thrust member, said last named means including a check valve and a resistance valve which open in opposite directions and permit liquid to flow freely from said source to said guiding portions and permit liquid to escape from said guiding portions only after the pressure therein exceeds the pressure at said source.

10. In a hydrodynamic machine, the combination of a rotatable cylinder barrel having a plurality of two-diameter cylinders each of which includes an outer guiding portion and a concentric inner pumping portion of smaller diameter, channels communicating with said pumping portions, valve means associated with said channels for controlling the flow of liquid 'to and from said pumping portions, a two-diameter piston arranged in each of said cylinders and having its larger portion fitted in the guiding portion thereof and its smaller portion tted in the pumping portion thereof, a thrust member engaging the outer ends of said pistons and so arranged in respect to said cylinder barrel as to cause the pistons on one side of said machine to move progressively inward during rotation of said cylinder barrel and to eject liquid from both the pumping portions and the guiding portions of the cylinders on that side oi said machine, channel means for interconnecting the guiding portions of all of said cylinders to enable liquid ejected by inward moving pistons from the guiding portions of the cylinders on said one side of said machine to flow to the guiding portions of the cylinders on the other' side of said machine and move outward the pistons in those cylinders, a source of pressure liquid other than said cylinders. and means for supplying liquid from said source to the guiding portions of said cylinders to initially move said pistons outward into contact with said thrust member, said last named means including a check valve and a resistance valve which open in opposite directions and permit liquid to ow freely from said source to said guiding portions and permit liquid to escape from said guiding portions only after the pressure therein Iexceeds the pressure at said source.

l1. In a hydrodynamic machine, the combination of a rotatable cylinder barrel having a plurality of two-diameter cylinders arranged therein in a circular row, each cylinder including an outer bore and a smaller inner bore, a twodiameter piston arranged in each cylinder and having its larger portion fltted in said outer bore and its smaller portion fitted in said inner bore l and forming a shoulder at its junction with said large portion, an annular thrust member arranged eccentric to said cylinder barrel and engaging the outer end of each piston to cause said piston to reciprocate in its cylinder during rotation of said cylinder barrel, a channel communicating with each of said inner bores, valve means for controlling said channels to thereby 14 control the ow of fluid to and from said cylinders, means for connecting said outer bores to each other to enable fluid expelled from the outer bores on one side of the machine by inward moving pistons to flow to the outer bores on the other side of the machine and move outward the pistons therein, a source of pressure fluid other than said cylinders, and means for supplying fluid from said source to said outer bores to act upon said shoulders and initially move said pistons into contact with said thrust member, said last named means including a combination check and resistance valve which permits fluid to iiow freely from said source to said outer bores and prevents fluid from escaping therefrom until after the pressure therein exceeds the pressure at said source.

WALTER FERRIS.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,069,651 Ferris Feb. 2, 1937 2,074,068 Ferris Mar. 16, 1937 2,229,715 Zimmerman Jan. 28, 1941 2,273,468 Ferris Feb. 17, 1942 2,292,181 Tucker Aug. 4, 1942 2,304,903 Eppens Dec. 15, 1942 2,345,446 Baker Mar. 28, 1942 2,391,221 Beeh Dec. 18, 1945 2,420,080 Huck May 6, 1947 2,462,931 Anderson Mar. 1, 1949 2,470,220 Mott May 17, 1949 2,484,337 Ferris Oct. 11, 1949 FOREIGN PATENTS Number Country Date 220,417 Great Britain 1924 

